Advanced AI Prompt for Docker Multi-Arch Build and ECR Push

Act as a Senior Cloud Infrastructure Engineer. Design a high-performance GitHub Actions workflow dedicated to building multi-architecture Docker images across [PLATFORMS] (e.g., `linux/amd64,linux/arm64`). The workflow must: 1) Authenticate securely with AWS ECR using OIDC (IAM Roles for GitHub Actions, explicitly avoiding hardcoded access keys). 2) Utilize `docker/setup-buildx-action` to build and push the image [IMAGE_NAME]. 3) Implement Docker layer caching utilizing the `gha` (GitHub Actions) cache backend to speed up subsequent builds. 4) Automatically tag the pushed images with both the short Git SHA and the 'latest' tag. Provide the specific AWS IAM policy JSON required for the OIDC role as a comment within the YAML.